Variable speed turning chute for raw material to be discharged

ABSTRACT

A variable speed turning chute for raw material to be discharged having an upper part and a lower part, each of which may be rotated in either a clockwise or counter-clockwise direction, at least two outlets of different dimensions formed in the lower part of the chute which correspond to the rotational locus of a board on the upper part of the chute for selectively closing off one of the outlets, and a turning ring which has engaging means thereon that allows the upper part of the chute to rotate relative to the lower part for a certain angle until one of the outlets is closed off by the board whereby the lower and upper parts of the chute are then rotated together in the same direction by a driving device provided at the upper part of the chute or, alternatively, at the lower part.

United States Patent [1 1 Yoshioka et al.

[4 1 Dec. 16,1975

1 1 VARIABLE SPEED TURNING CHUTE FOR RAw MATERIAL TO BE DISCHARGED [73]Assignee: Nippon Steel Corporation, Tokyo,

Japan 22 Filed: Dec. 20, 1973 21 Appl. No.: 426,812

[30] Foreign Application Priority Data 3,780,887 12/1973 Bottoms..2l4/l7 CB Primary ExaminerRichard A. Schacher Assistant ExaminerJamesL. Rowland Attorney, Agent, or Firm-Toren, McGeady and Stanger [5 7]ABSTRACT A variable speed turning chute for raw material to bedischarged having an upper part and a lower part, each of which may berotated in either a clockwise or counter-clockwise direction, at leasttwo outlets of different dimensions formed in the lower part of thechute which correspond to the rotational locus of a board on the upperpart of the chute for selectively closing off one of the outlets, and aturning ring which has engaging means thereon that allows the upper partof the chute to rotate relative to the lower part for a certain angleuntil one of the outlets is closed off by the board whereby the lowerand upper parts of the chute are then rotated together in the samedirection by a driving device provided at the upper part of the chuteor, alternatively, at the lower part.

9 Claims, 6 Drawing Figures US. Patent Dec. 16, 1975 Sheet10f2 3,926,289

FIG.I

Fl e. 3b

US. Patent Dec. 16, 1975 Sheet 2 of2 3,926,289

FIG.4

VARIABLE SPEED TURNING CHUTE FOR RAW MATERIAL TO BE DISCHARGED SUMMARYOF THE INVENTION The present invention relates to a turning chute forraw material to be charged by which raw materials are uniformly chargedto, for example, an ore storage hopper, etc., in which the outflow speedof the dis-' charged raw material is varied freely so that various rawmaterials with different fluidity can be distributed in an optimummanner.

A turning chute has been employed conventionally in many applications,and particularly in a blast furnace it has been used at the top of theraw material charging part since many years ago a uniform distributionof the charged raw materials was required in its operations.

In a blast furnace operation, the use of pellets has been requiredbecause of the recent ore situation and for the purpose of furtherlowering the coke ratio, therefore development of such an apparatusadapted for the charging of large volume of pellets is desired.

One of the problems in charging large amounts of raw material is thatthe discharging apparatus should be able to distribute not only pelletsthat flow easily, but also differently shaped materials such as sinteredore, coke, etc., that do not flow as easily.

In a continuously turning chute of a conventional charging apparatus,uniform distribution is secured by scattering raw materials which fall.and flow out of a skip car or a conveyor, and the uniformdistribution ofthe raw materials can be secured by accumulating raw materials in theturning chute and by increasing the number of piled layers of rawmaterials scattered.

For that end it is desired to accumulate raw materials within the chuteand to make the time of the raw materials pass through the tuming chuteas long as the charging schedule permits.

However, in the case of a conveyer charging system, the charging timecan be as long as several tens of seconds. This means that a largenumber of piled layers can be formed. This, however, is difficult tocontrol since it is hard to prevent the overflow of large accumulationsof raw material in the chute. In this conveyer system, charging of bothcoke and pellets, both of which have different degrees of fluidity,cannot be achieved by using a conventional turning chute having anoutlet that would be used for both the charging of either coke orpellets. On the other hand, in the case of skin charging, accumulationof the raw material can be realized, but the charging through the sameoutlet of both pellets, coke, etc. inevitably affects the speed thatthey pass through the outlet due to their inherent flow characteristics.This leads to unwanted differences in distribution which simply cannotbe eliminated.

That is, as the fluidity becomes greater, the flow out time is reducedand as a result the number of piled layers is reduced and thedistribution tends to become poor. In case of pellets, the abovetendency is conspicuous and good distribution cannot be secured by theoutlet diameter of the turning chute-asdetermined by the passing time ofcoke having the lowest fluidity among the materials. When the outletdiameter of the turning chute is reduced to such a size as to achievethe number of piled layers required for distribution of pellets, theoutflow time of coke becomes quite longer.

The increase in the outflow time of raw materials from the turningchute-reduces the number of charges possible per day and makes theopening time of the seal valve longer. Also the time during whichdifferential pressure works on the top and bottom of the small bellbecomes longer, which will shorten the life of the small bell.

Therefore the present invention is intended to overcome the problem ofdifference in the fluidity of various raw materials charged and toprovide a turning chute in which outlets suited for each of the rawmaterials'are prepared beforehand and one of the same is selected asnecessary, thus controlling the outflow speed of each of the rawmaterials. The invention is characterized by that a variable speeddevice for outflowing raw materials is so formed that a turning chute isformed by dividing the same into an upper part (A) of the chute and thelower part (B) of the chute, rotation of each one of which can bereversed, and at the same time at least two or more of outlets havingdifferent diameters are provided at such a position on the lower part(B) as corresponding to the rotational locus of a lower port of theupper part (A) Furthermore, a turning ring having engaging means thereonallows the upper part of the chute to rotate relative to the lower partof the chute for a certain, predetermined angle so that the board on theupper part of the chute covers a selected outlet on the lower part, atwhich point both the upper and lower parts rotate together.

BRIEF DESCRIPTION OF THE DRAWING Next the present invention shall beexplained in detail by examples shown in the drawings.

FIG. 1 is a vertical sectional view of the device of the presentinvention. FIG. 2 is a detailed drawing of a part (a in FIG. 1. FIG. 3 aand FIG. 3b are schematic drawings of the turning ring mechanism in thepresent invention. FIG. 4 is a schematic drawing of another example ofthe present invention. FIG. 5 is a schematic drawing of a guide shade inFIG. 4.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1, (l) is an ore receivinghopper (or a conveyer chute), (2) is an ore storage hopper (or adistribution chute), and there is provided therebetween the turningchute (3) of the present invention.

The turning chute (3) is so formed as being divided into'an upper part(A) and a lower part (B), each one of which can have its rotationreversed.

A side wall part (4) of the upper part (A) is gradually inclined to dropand guide raw materials to be charged and at the same time a lower port(5) (refer to FIGS. 3a and 3b) is formed at the lower portion.

A coke outlet (6,) and a pellet outlet (6 having a little smallerdiameter than that of the coke outlet (6 are provided at the lower part(B) of the chute, and the two outlets (6 (6 are provided at suchpositions as being on the same circumference with the rotation locus (P)(refer to FIGS. 3a and 3b) of the lower port (5) of the upper part.(A).In the embodiment shown in FIGS. 1-5, the outlets (6 and (6 arepositioned from each other when measured along the circumference (P). Itis to be noted, however, that any suitable number of outlets may beprovided, not just two, with appropriate, angular separations betweenthem.

A turning ring (8) is provided between the upper part (A) and the lowerpart (B), and it has such a structure that the lower port (5 of theupper part (A) can select the outlet suitable for the raw material to becharged as necessary. The structure of the turning ring (8) is 3 shownin FIG. 2 and FIGS. 3a and 3b in which a ring (9) on the upper part (A)and a ring (10) on the lower part (B) are assembled together with asteel ball (11) being positioned therebetween.

The rings (9) 10) of the turning ring (8) have stoppers so that theupper part (A) and the lower part (B) can rotate relative to each otherfor a predetermined angle. Two stoppers (II) (III) are provided at theouter circumference of the ring (9) of the upper part (A) with 180interval, while one stopper (I) is formed at the inner circumference ofthe ring (10) of the lower part (B), so that they can rotate relativelyas much as 180. Naturally the position and the number of the stoppers ofthe ring (9) of the upper part (A) can be suitably determined based onthe position and the number of the outlets provided, and when three ormore of the same are to be provided, such stoppers should be so made asfreely coming out and in at the side face of the turning rings. Whilesuch number of stoppers as corresponding to the number of the outlets(6) are provided on the ring (9) of the upper part (A) in this example,an opposite arrangement is also possible; that is such a number ofstoppers as corresponding to the number of the outlets (6) may beprovided on the ring (10) of the lower part (B).

Next, the function of the chute shall be explained by referring to FIGS.3a and 3b. When the upper part (A) is rotated in a forward direction (asshown by an arrow) from its stationary position as shown in FIG. 3a, theupper part (A) moves until the stopper (II) of the ring (9) engages withthe stopper (I) of the ring (10) on the lower part (B), while the ring(10) of the lower part (B) stays in a stationary state. In a statewherein stoppers (I) and (II) engage together, in other words the lowerport of the upper part (A) is connected through with the outlet (6 forcoke, the outlet side ring is pushed by the upper part (A) thus makingcombined rotation. On the other hand, when the upper part (A) is rotatedin a reverse direction as shown in FIG. 3b (as shown by an arrow), thering (10) of the lower part (B) stays in a stationary position until thestoppers (I) (III) engage with each other, and when they are engaged, inother words, when the lower port (5) of the upper part (A) is connectedthrough with the outlet (6 for pellets at the lower part (B), the lowerpart (B) is pushed by the upper part (A) and thus causing combinedrotation of both parts.

At that time a brake (12) is provided at the circumference of the ring(10) of the lower part (B) or on lower part (B) itself to provide abraking torque on the lower part (B) in a direction opposite to therotating direction, so that the ring (10) of the lower part (B) will notmove before the stoppers of both rings (9) (l0) engage together.Therefore, there will be no shifting or deviation between both ringswhile both rings are being rotated as their stoppers are engagedtogether by reduction in the speed of the turning chute or other causes.

(13) is a driving device to turn the turning chute and is adjacentlyconnected to the upper part (A), but it may be adjacently connected tothe lower part (B) as necessary.

Because of the necessity for reverse rotation in this example, a directcurrent motor is employed in the driving apparatus (13), but an AC.motor may also be used. The motor (20) rotates the turning chute (3)through a pinion (l8) and a ring gear (19).

In the drawing, (14) is a roll for preventing the upper part (A) fromvertical displacement, (15) is a holding roll against centrifugal force,and (16) is a supporting roll.

FIG. 4 shows another example of the present invention, wherein a turningchute (3) is divided into an upper part (A) and a lower part (B) as inthe above mentioned example. The lower part (B) has two or more outlets,for example a coke outlet (6 and a pellet outlet (6 wherein thedifference from the above mentioned example is that a guide shade 17) isprovided in the upper part (A) to guide the raw materials charged, andthe guide shade (17) has spiral plates (17 (17 composed symmetricallyand has a lower port (5) formed at its bottom.

The mechanism for the lower port (5) selects outlets (6) in the lowerpart (B) in the same manner as indicated in the above mentioned example.

The raw material to be charged is guided by the spiral shaped inclinedface of the guide shade (l7) and is charged into a storage hopper (2)(or a distribution hopper) while being rotated from outlets 6) which aresuitably selected and are connected through.

While in this example a turning driving device (13) is adjacentlyconnected to the lower part (B), it may be provided at the abovementioned upper part (A).

As has been explained in detail according to the device of the presentinvention, as such outlets can be suitably selected as corresponding toeach raw material to be charged, the charging speed of the raw materialscan be appropriately controlled, and as a result, for example in a blastfurnace uniform, distribution of raw materials to be charged can bemaintained in the blast furnace. Very satisfactory results can beobtained in operations, and thus has great practical values.

What is claimed is:

1. A variable speed turning chute for raw materials to be discharged,comprising an upper part rotatable about an axis having means forguiding the raw material therethrough, a rotatable lower part mountedbelow said upper part and coaxial therewith, said lower part having twooutlets formed therein, one of said outlets discharging the raw materialguided to it by said means for guiding the raw material, driving meansoperatively connected to one of said upper and lower parts, and meansinterconnected between said upper and lower parts for maintaining saidparts freely rotatable relative to each other for a predetermined angleand thereafter effecting engagement between said upper and lower partsfor rotation thereof in unison so that one of said outlets of said lowerpart may be selectively aligned with said means for guiding the rawmaterial, whereby raw material of different flow characteristics may bedischarged through one of said outlets designed specifically therefor.

2. A variable speed turning chute according to claim 1 wherein saidupper part comprises a slanted side wall, said means for guiding the rawmaterial comprising said side wall and a port located at the bottom ofsaid wall proximate said lower part, whereby the raw material is guideddown said side wall by gravity and exits through said port to one ofsaid outlets of said lower part.

3. A variable speed turning chute according to claim 1 wherein one ofsaid outlets of said lower part is of a different size than the other sothat each outlet operates for discharging a particular predeterminedtype of raw material.

4. A variable speed chute according to claim 1, wherein said meansconnected to both of said upper and lower parts comprises a turning ringhaving a first portion mounted to the bottom of said upper part, and asecond portion mounted to the top of said bottom part, each of saidfirst and second portions having engaging means thereon for permittingrelative rotation of said upper part relative said lower part until theengaging means of said first portion contacts the engaging means of saidsecond portion.

5. A variable speed chute according to claim 4, wherein said lower partcomprises two outlets angularly spaced 180 apart, said engaging means ofsaid first portion comprising two stops extending outwardly in adirection away from said means for guiding the raw material and spaced180 apart on the circumference of said first portion, said engagingmeans of said second portion comprising one stop extending inwardly fromsaid second portion in a direction toward said outlets,

said one stop situated along a line connecting the centers of said twooutlets.

6. A variable speed chute according to claim 5, further comprising brakemeans for applying a braking torque to said second portion to assureproper contact between said engaging means on said first and secondportions.

7. A variable speed chute according to claim 1, wherein said drivingmeans rotates said upper and lower parts in either a clockwise orcounterclockwise direction.

8. A variable speed chute according to claim 1, wherein said means forguiding the raw material comprises a guide chute mounted inside saidupper part and including two spiral plates for guiding the raw materialtherealong and down to one of said outlets.

9. A variable speed chute according to claim 1, wherein said outlets arecircularly shaped, each of said outlets having a diameter different fromthat of the

1. A variable speed turning chute for raw materials to be discharged,comprising an upper part rotatable about an axis having means forguiding the raw material therethrough, a rotatable lower part mountedbelow said upper part and coaxial therewith, said lower part having twooutlets formed therein, one of said outlets discharging the raw materialguided to it by said means for guiding the raw material, driving meansoperatively connected to one of said upper and lower parts, and meansinterconnected between said upper and lower parts for maintaining saidparts freely rotatable relative to each other for a predetermined angleand thereafter effecting engagement between said upper and lower partsfor rotation thereof in unison so that one of said outlets of said lowerpart may be selectively aligned with said means for guiding the rawmaterial, whereby raw material of different flow characteristics may bedischarged through one of said outlets designed specifically therefor.2. A variable speed turning chute according to claim 1 wherein saidupper part comprises a slanted side wall, said means for guiding the rawmaterial comprising said side wall and a port located at the bottom ofsaid wall proximate said lower part, whereby the raw material is guideddown said side wall by gravity and exits through said port to one ofsaid outlets of said lower part.
 3. A variable speed turning chuteaccording to claim 1 wherein one of said outlets of said lower part isof a different size than the other so that each outlet operates fordischarging a particular predetermined type of raw material.
 4. Avariable speed chute according to claim 1, wherein said means connectedto both of said upper and lower parts comprises a turning ring having afirst portion mounted to the bottom of said upper part, and a secondportion mounted to the top of said bottom part, each of said first andsecond portions having engaging means thereon for permitting relativerotation of said upper part relative to said lower part until theengaging means of said first portion contacts thE engaging means of saidsecond portion.
 5. A variable speed chute according to claim 4, whereinsaid lower part comprises two outlets angularly spaced 180* apart, saidengaging means of said first portion comprising two stops extendingoutwardly in a direction away from said means for guiding the rawmaterial and spaced 180* apart on the circumference of said firstportion, said engaging means of said second portion comprising one stopextending inwardly from said second portion in a direction toward saidoutlets, said one stop situated along a line connecting the centers ofsaid two outlets.
 6. A variable speed chute according to claim 5,further comprising brake means for applying a braking torque to saidsecond portion to assure proper contact between said engaging means onsaid first and second portions.
 7. A variable speed chute according toclaim 1, wherein said driving means rotates said upper and lower partsin either a clockwise or counterclockwise direction.
 8. A variable speedchute according to claim 1, wherein said means for guiding the rawmaterial comprises a guide chute mounted inside said upper part andincluding two spiral plates for guiding the raw material therealong anddown to one of said outlets.
 9. A variable speed chute according toclaim 1, wherein said outlets are circularly shaped, each of saidoutlets having a diameter different from that of the others.